DOW-UAP-D129, AAWSAP DIRD, ספינטרוניקה מתכתית, מרץ 2010

Metallic Spintronics
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Contents
Figures
Figure 1. In a Magnetic Multilayer, Several Atomic Layers of Magnetic Material
Alternate With Layers of Nonmagnetic Material ...................................... 1
Figure 2. Resistance of a Magnetic Multilayer R Versus Magnetic Field .................. 2
Figure 3. Differential Resistance dV/dI of a Mechanical Point Contact as a Function
Figure 6. Torques on a Magnetic Moment in a Magnetic Field and Subject to an
Figure 9. Scanning Transmission X-ray Microscopy Images ................................. 10
Figure 12. Schematic of Point Contact to Sample Geometry ................................. 15
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Metallic Spintroni·cs
1. Introduction
The rapid pace of progress in the computer industry over the past 40
years has been based on the miniaturization of chips and other
computer components. Further miniaturization, however, faces
serious challenges-for example, increasingly high power dissipation.
To continue on pace, the industry must g,o beyond incremental
improvements and embrace radically new technologies. A promising
nanoscale technology known as spintronics (a neologism for "spin­
based electronics"} has emerged. Spintronics refers to the role an
electron spin plays in solid-state physics. Spintronics researchers
aim to develop a revolutionary new class of electronic devices based
on the spin of electrons in addition to the charge. In spintronic
devices, information is carried not by the electron's charge, as in
conventional microchips, but by the electron's intrinsic spin.
Changing the spin of an electron is faster and requires less power
than moving it. Therefore, if a reliable way could be found to control
and manipulate spins, spintronic devices could offer higher data
processing speeds, lower electricity consumption, and many other
advantages over conventional chips, perhaps including the ability to
carry out radically new quantum computations.
Spintronics in ferromagnetic systems is built on a complementary
set of phenomena in which the magnetic configuration of the system
influences its transport properties and vice versa. Giant
magnetoresistance (GMR} (Reference 1, 2} and spin-transfer-torque
(STT} (Reference 3-5} phenomena exemplify such interconnections
in multilayers composed of ferromagnetic (F} and nonmagnetic (N)
layers. The physics and app…